Tracing the mixing efficiency of a primary mesophilic anaerobic digester in a municipal wastewater treatment plant

Abstract

Mixing is one of the most important operations in high-rate digesters because it maintains uniformity within the digester and prevents scum accumulation. The mixing of anaerobic digester contents significantly influences the efficiency of digestion bioprocesses. Hydraulic dead zones in the reactor reduce the effective hydraulic retention time and, thus, have detrimental effects on the reaction kinetics. In this study, the efficiency of mixing by gas recirculation was examined in a digester of the Haifa Wastewater Treatment Plant (HWWTP).